High-grade gliomas are the commonest primary malignant brain tumours in adults, affecting approximately 5000 people per year in the UK. Standard treatment comprises a combination of surgery, radiotherapy and chemotherapy; however this condition remains incurable and the average survival is approximately 18 months from diagnosis. There are a number of reasons for this. Firstly these tumours are highly invasive and involve important areas of brain making it impossible to remove them surgically or cure them with radiotherapy. In the majority of cases the tumour recurs within 2 to 3cm of the original site of tumour removal. Secondly, due to the presence of a barrier between the bloodstream and the brain, when drugs designed to kill tumour cells (chemotherapy) are given intravenously or orally, they frequently do not reach the tumour at a sufficient dose to have a beneficial effect. As the chemotherapy dose has to be very high for a sufficient dose to reach the tumour, drug-related side-effects are common.